Improvement in the process of making white lead



H. HANNEN.

Making White Lead.

No. 18.244. Patented Sept. 22, 1857.

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UNITED STATES PATENT OFFICE.

HENRY l-lANNEN, OF DUBUQUE, IOWA.

IMPROVEMENT IN THE PROCESS OF MAKING WHITE LEAD.

Specification forming part of Letters Patent No. 18,244, dated September 22, 1857.

To all whom it may concern.-

Be it known that L'HENRY HANNEN, of the city and county of Dubuque, in the State of Iowa, have invented a certain new and useful Improvement in the Process of Manufacturing WVhite Lead, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, in which Figure 1 represents a plan of an apparatus suitable for carrying my improvement into effect, the top of one chamber being removed to exhibit the arrangement of the parts of the interior, the top and slats of another chamher for the support of the lead to be carbonated being also removed to show the arrangement of pipes for the admission of steam and the vapor of acetic acid. Fig. 2 represents an end View of the same. Fig. represents avertical longitudinal section taken through the line X X, Fig. 1. Fig. at represents a vertical transverse section through the line 5% 7;! of Fig; 1.

My improvement consists in subjecting the lead to the action of steam and atmospheric air for the purpose of oxidation, then to the vapor of acetic acid in order to form the subacetate, and afterward to the action of carbonic acid alternately and successively until the operation is complete, whereby the metal becomes carbonated in a more speedy, regular, and effectual manner than where the metal is exposed to the action of the air, vapor of hydrated aceticacid, and carbonic acid con jointly.

In order to show how this process may be carried into effect, I will now proceed to describe an apparatus suitable for such a purpose.

In the accompanying drawings, A and A represent two series of quadrangular wooden chambers of any desired number arranged and runningparallel with each other. Through the lower part of each chamber is passed a pipe B, which connects at one end with the main pipe 0, leading from the boiler D, that contains the acetic acid,and at the other end with the steam -pipe E, leading from the boiler F. Each of these pipes is provided with stop-cocks e, by means of which the steam and vapors may be admitted to the room or shut off, as desired. From the pipe B two series of pipes a branch out on either side parallel with the bottom of the chambers and extending nearly to their sides. Through these branch pipes are pierced a number of h0lesa rowon each side and one on the topfor the purpose of distributing through the chamber the vapors admitted into the main pipe B. Into each of these chambers, commencing a little above the pipes to, are arranged a series of ranges of slats l) at suitable distances apart for the reception of the coils of lead and upon which they are placed, a small space in the center of the chamber being reserved for a chimney 0, consisting of a tube formed of any suitable material and pierced with a number of holes for the admission of the vapors from the room and by which they are carried into the open air. By means of this chimney the vapors or gases are equally diffused throughout the chambers by means of a valve d, fitted to its mouth, inasmuch as when the valve is closed the cold air on the outside, acting upon the walls of the chambers, draws the vapors to ward them and condenses them; but by opening the valve d a draft is immediately created in the room and the gases drawn toward its center.

Through the top of the chambers are pierced several holes fin this instance four in numbereach of which is furnished with valves g and attached to each other in pairs by means of connecting-rods 7b, the object of which is to enable the operatives to permit or prevent the escape of the gases and vapors as required. The sides of the chambers near the bottom are also pierced with a number of holes 1', provided with stoppers or valves, by means of which the admission of air or the escape of gases, if thought advisable, is regulated.

Upon the side of the chambers facing each other and near their top are arranged main pipes G, communicating with and leading from a gas chamber or reservoir H. From this branch pipes I lead into the upper part of the chambers, through which the carbonicacid gas is carried from the reservoir H as it is generated from the furnace K (which may or may not generate the steam or vapor of the acetic acid) and diffused throughout the chanr belgit having a tendency to fall toward the b0ttom by virtue of its superior specific gravity. Each of the branch pipes I is provided with stop-cocks n, by means of which the supply is regulated or cut off, as required. The furnace K, which generates the carbonic acid, is furnished with two chimneys and slides or valves for each, one L leading into the open air and the other M into the gas-chamber H, so that when a fresh supply of fuel has been added to the furnace the chimney leading to the chamber may be closed by its valve until all the smoke and other impurities have been driven off through the chimney leading to the atmosphere, after which the valve of the latter is closed and that of the former opened for the admission and collection of the gas, whence it is carried and diffused throughout the chambers A by means of the main G and branch pipes I, as before described.

Each of the chambers is provided with a door J, by means of which the operatives 6f.- fect an entrance either to supply fresh lead to undergo the process orto take away that which has already undergone it. For the purposes of grinding, &c., these doors are made to fit with great exactness to prevent the escape of the gases, and are secured by means of cross-bars Z or in any other suitable manner. In each door is placed a plate or pane of glass hi, there being others arranged in the rear side of each chamber to enable the attendants to watch the progress of the process.

In order to keep up the requisite temperature of the room,a steam-chamber may be formed underneath the bottoms of the chambers, into which steam may be passed either directly from the boiler F or from the steampipe E, that supplies the chambers.

From the foregoing description of the apparatus my process will be easily understood, to wit: The rolls or coils of lead having been arranged upon the slats b and the doors J and valves 9 closed, the plugs or valves of the airholest' are opened and the stop-cocks e of the steam-pipes E turned to give free ingress to the steam, which, passing along the pipe B into the perforated branch pipes a, is diffused throughout the chambers. They are left in this condition until a thick coating of the oxide has been formed. The steam is then shut off and the valves g opened for a short time to permit its escape and then closed, after which the stop-cocks e of the pipe C are turned, which permits the vapor of the acetic acid to enter the pipe B and be diffused in the same manner as the steam throughout the chambers, which immediately commences to act upon the oxide forming the subacetate of lead. Immediately upon the completion of this part of the process, sufficient time having been allowed for that purpose, the acetic vapors are shut off by turning the stop-cock e and the valve 9 again opened to permit their escape and again closed, and the carbonicacid gas permitted to enter by turning the stop-cock n of the pipe G, leading from the gas-chamber H. The carbonic-acid gas speedily decomposes the acetate forming the carbonate of lead, after which it in turn is shut off and the valves opened to permit its escape and the steam and air again admitted, and so on alternately and successively until the whole has become carbonated, after which it is removed and a fresh supply put in its place to undergo the same operation.

Having thus described my improved process of manufacturing white lead, what I claim as new, and desireto secure by Letters Patent, 1s-

Subjecting the lead and the compounds formed therefrom by the agents employed for this purpose to the action of steam and air, vapor of acetic acid, and carbonic-acid gas alternately and successively until the process is complete, in the manner substantially as and for the purposes set forth.

In testimony whereof I hereunto set my hand this 3d day of April, A. D. 1857.

HENRY HANNEN. Witnesses:

P. HANNAY, W. LESKI. 

